I have about 4 hours of video I want to burn to DVD (family video with menu). Do I have to make separate files that'll fit on one DVD at a time? Or can I have one project file and it'll have me put in additional DVDs when it's out of space?
You need to divide up the project into separate parts that will fit on individual DVDs.
Meaning, separate project files? Or is there a way to do this within a single project?
Sorry, not with a single project.
If the video is SD, you may want to consider creating a Blu-ray disc. A single Blu-ray disc will hold that.
You will, however, need to use another app to author and burn it.